Night Vision and Thermal Systems

IR Illuminators – Invisibe Infrared Light Flashlights

An infrared light, commonly abbreviated as IR, is an electromagnetic radiation emitted in a longer wavelength than the visible light, with an approximated frequency range of 1 to 400 THz which also covers the range of thermal radiation of objects with temperature close to 67.9 to 70.7˚F or normal room temperature.

The International Commission on Illumination (CIE) suggested a categorization of infrared radiation into the following bands: a) Near-Infrared, NIR / IR-A (700 nm to 1,400 nm or 0.7 μm to 1.4 μm; 215 THz to 430 THz); b) Short-Wavelength Infrared, SWIR / IR-B (1,400 nm to 3,00 nm or 1.4 μm to 3 μm; 100 THz to 215 THz); and c) Mid-Wavelength to Long-Wavelength MWIR / LWIR / IR-C (3,000 nm to 1mm or 3 μm to 1,000 μm; 300 GHz to 100 THz).

Night vision technology has proven its purpose, primarily, in military operations, hunting, nature and astronomical observations, law enforcement activities. Various night vision devices are used at low lighting conditions such as covert operations, search and rescue after serious accidents when response time mean life along with nature wildlife observation which usually is most active at dusk or even night time, when pressure from human beings are lowest possible and nature creatures can move stealthily.

So far, there are three main functions in the industrial set up or types of infrared illuminators that were identified being released in the market, namely, infrared laser illuminators, infrared led illuminators and infrared filters installed in front of “standard” light sources like spotlights and flashlights with visible to human eyes spectrum.

PEO PEQ 15 Infrared Laser Illuminator

PEO PEQ 15 Infrared Laser Illuminator

Based on laser diode technology, infrared laser illuminators are most powerful from available for public as have ability throw very concentrated beam of light to far away distances while maintaining superb image quality on even low amount light amplification devices like Generation 1 and Generation 1+ (usually around x1000 on good Gen 1+ image intensifier). Infrared lasers are also often adapted for use in military, LEO and hunting application where tight beam of infrared light are used for target designation at night time. Combined devices with various functions like infrared illuminator and IR target designator in one are available for LEO and military personnel.

This type of illuminator can also be very harmful for the eyes if not properly dealt with, due to the concentration of light in the particular wavelength within which it normally functions.

Infrared led illuminators are used as standard source artificial light for most of night vision devices made for civilian market like night vision rifle scopes, night vision monoculars and binoculars, goggles and so on as infrared led provide relatively safe IR light source which is still useful at short to mid ranges without damaging night vision image intensifiers via excessive light.

Although led infrared light is more safe then IR laser diode, devices based on this technology still must be used with safety in mind as throwing excessive light in your eyes or night vision device can leave serious damage to both of them.

Infrared LED technology also are widely used in the electronics industry since it is the least expensive among the other types of infrared illuminator, which comes as a small, cheap and with a shorter range of luminance capacity. It is a semi-conductor source of light, used as indicator or display for devices. It is usually seen with the red or amber hue, though nowadays, it already covers almost the entire color wavelength. It is typically seen in a system of mobile and portable gadgets such as remote controls of appliances and equipments. They require moderate amount of power source such as through a solo or dual 1.5v battery package to function.

Infrared filters, which are also known as infrared cut-off filters, were designed to absorb visible light and the other wavelengths except for the mid-infrared range. This is commonly installed in front of various halogen or other incandescent light bulbs and used as artificial light source for older type of night vision devices (usually Generation 0 or Generation 1 like German made Ferro 51 or Soviet PPN-2 night vision) for multiplying low light.

Although light from infrared illuminators are not fully visible for humans and animals, continuous such light exposure to eyes can cause serious and permanent damage including blindness, thus, proper handling is needed for equipments with infrared illuminators installed.

Categorised as: Night Vision

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